I would add underskinning and strakes first and see how the boat runs--before adding a third toon. With 90 hp, it may suit your needs just fine.ronb wrote:I haven't seen it mentioned on here, but adding strakes to the outside of the tubes will cause it to 'dig' if you try cornering when you are at running speed. Last year I had the opportunity to use a Bennington with strakes and I did not expect that when I made a sharp(ish) turn under full throttle. It dug so hard that it splashed water up and over the railing. My SouthBay does not have any strakes. I've been thinking that I'd add a larger diameter center tube before adding strakes.
I am running a 90hp, maxing out around 24MPH on a clear day with no wind and just the 4 of us (2 adults, 2 kids under 40lbs each). There is another guy on my lake with a SouthBay 925CR with a tri-toon and a 115HP Merc and he was claiming 35MPH. Could be fish stories, but after the experience with the Benny and strakes, I'm going to try the third tube first.
Just food for thought..
Adding a larger center toon may be asking for trouble, as you don't have the engineering resources of the manufacturer. They spend quite a bit of time on the water with tritoons and strakes.
Some manufacturers put stakes on inside and outside of two toons. Some with 3 toons put them on the inside of the outside toons and on both sides of the center toon. One major manufacturer puts on both sides of all toons. To me, if the nosecone is out of the water, the strakes are doing their job.
The third toon adds a couple of hundred pounds and increases drag. Straight ahead performance with 25" toons and strakes will probably be slightly better than the tritoon. The tritoon will handle better and increase weight carrying capacity, however. The same size third toon is really best with 115 hp or 150 hp motors.
